Assessment of Nitrous Oxide Contamination in Pediatric Operating Rooms in Iran, Tehran and Shahid Beheshti University Hospitals

The hazards of contact with low concentrations of anesthetics are undeniable. Nowadays N2O is one of the most common drugs used in anesthesia. The aim of this study is to assess the nitrous oxide contamination in pediatric operating rooms in Iran, Tehran and Shahid Beheshti University hospitals. This descriptive study was conducted in 15 pediatric operating rooms in 4 main pediatric educational hospitals. The rooms with continuous usage of N2O with 2-3 lit/min of flow for general anesthesia in pediatric operations were studied. For sampling and detection of N2O concentration in parts per million, a portable IR spectrophotometer(3010 model of Bacharach Inc.) was utilized. The sampling was done in 6 different points of the operating rooms and 3 different hours of work time(8:30-9AM, 10:30-11AM and 12:30-1:00PM). Independent t-test and one-way ANOVA were used to compare the means. There was no significant difference between the means of N2O concentration in different points of the operating rooms(2248±2202, 1325±1237, 1346±1234, 1792±1706, 2615±2590 and 2414±2593, P>0.05). The mean of N2O concentration in different points of operating rooms with standard ventilation system was significantly lower than that of operating rooms without standard ventilation. The kind of anesthesia, anesthesia system(with mask or endotracheal cuffed or without cuff tube), work time, the position of operating room door(opened or closed), and also the cooler(on/off) exert no significant difference on the mean of N2O concentration. The mean of N2O concentration in different points of pediatric operating rooms of educational hospitals is much higher than standards.